We're using Unity 2019.3.3f1, Wwise 2019.2.1.7250, and pretty much the default Unity Wwise integration from the launcher. We also use versioning (and have the appropriate setting checked in the Wwise project settings)
Overview of the problem : We can't get anything from Wwise to Unity pretty much. Opening the editor, refreshing the project, and generating soundbanks all generate errors from Unity. Changes to already working events are not updated, and nothing new can come through...
I've put the errors below, any fix for this would be greatly appreciated! Thanks!
The error we get upon editor start-up:

The error we get whenever we refresh:

Finally, the error we get whenever the Wwise integration tries to Populate:
